1. Field of the Invention
The present invention relates generally to devices and methods for ligating tissue of a patient, and more particularly, to a device and method particularly suitable for ligating hemorrhoids or other regions of inverted tissue.
2. Background Discussion
Hemorrhoids are swollen, often painful veins in the lower portion of the rectum or anus. It is a relatively common disease, the symptoms of which can include anal itching and/or aches and pains, particularly when sitting, blood in the stool, pain during bowel movements, and/or hard or tender lumps near the anus. Hemorrhoids are caused by increased pressure in the veins around the anus, which can occur as a result of pregnancy or childbirth, prolonged constipation, long periods of sitting, infections or the like.
Three to four different stages of hemorrhoid occurrence are known, with various stages of treatment depending on the severity. For the less severe cases, corticosteroid creams or lidocaine creams can reduce pain and/or swelling. For more severe cases that do not respond to topical treatments, various heat treatments can be attempted the objective of which is to shrink the hemorrhoids. For severe cases surgical intervention may be necessary.
Known surgical techniques for treating severe hemorrhoids include hermorrhoidectomy, which involves surgically removing the hemorrhoid, and rubber band ligation techniques. Rubber band ligation involves grasping the bulging hemorrhoid with a suitable surgical instrument, and placing a rubber band or the like around the base of the hemorrhoid. The rubber band strangulates the hemorrhoid knot and cuts off the blood supply. After a period of about 7 days, the hemorrhoid shrivels and dies, and falls off along with the rubber band. Scar tissue forms that continues to hold the veins in place, preventing future bulging.
A significant disadvantage of the rubber band ligation devices and techniques currently on the market is the risk of severe bleeding, which can be fatal. Severe bleeding can occur if the rubber band slips off the hemorrhoid too early (i.e., within the first 7 days). In these instances, postoperative pain and acute bleeding causes a sphincter spasm. Blood will then fill the rectum, or with mild bleeding the colon descendens. When the ampulla recti is filled with a certain amount of blood the patient feels the urge for defecation. A blood loss of up to one liter (20% blood loss) is possible. The consequences of bleeding can be severe and fatal, since often the bleeding will occur while the patient is at home and does not otherwise notice the blood loss until it reaches a critical level and causes hypovolaemic shock.
Thus, there is a need for an improved device and method for surgical ligation of hemorrhoids that reduces the risk that bleeding will occur.